The Challenge of Geriatric Pain
Steven A. King, MD, MS
Persistent pain is not an inevitable part of aging, but it is, unfortunately, fairly common among those aged 65 years and older. Between 25% and 50% of the general geriatric population and 45% to 80% of those in nursing homes have this problem.1
Pain is less likely to be adequately controlled in older persons than in younger adults, despite guidelines for the management of geriatric pain.1-3 Several factors appear to be involved in this unfortunate reality.
In the older population, the treatment of pain can be fraught with multiple problems that are far less likely to occur in younger adults. Even trying to determine the presence or level of pain can be difficult. Pain is a subjective concern; clinicians usually depend on the patient to identify pain and its severity.
Many geriatric patients have impairments in communication because of health problems, such as strokes and dementia. Thus, commonly used instruments to assess pain—such as the Visual Analogue Scale and the Verbal Numeric Rating Scale—may have a limited role for these patients. Other instruments, most of which were originally developed for young children, have been used for older patients. These include the Faces Scale (in which patients rate their level of discomfort based on facial expressions that range from smiling to crying) and the Pain Thermometer (which uses the image of a thermometer and asks the patient to rate the pain according to the image).4,5 However, even simple scales require some ability to communicate if valid and useful information is to be obtained.
The difficulty in assessing pain in noncommunicative geriatric patients is probably the major reason this group is even less likely to receive adequate pain management than the rest of the geriatric cohort.2,6 Clinicians may fail to consider a patient’s impaired ability to communicate and may rely instead on self-report rather than observing the patient for signs that might indicate pain (such as grimacing or inability to sit or lie comfortably).
Unfortunately, even when physicians do recognize the presence of pain, their attempts to alleviate it may fail because they do not take into account the patient’s general health status. For example, analgesics are often prescribed for hospitalized patients on an as-needed (prn) basis. Obviously, patients who are unable to communicate cannot ask for medications to relieve their pain. Physicians may feel they have addressed the pain by prescribing prn analgesics without recognizing that it is unlikely that patients will ever receive these drugs.
Failure to control pain adequately can have pernicious effects. A study examining pain in older men found that it was associated with increased frailty—itself a predictor of additional health problems and death.7 The study also found that mood may be a more important factor in the association between pain and frailty than physical illnesses. This finding highlights the importance of a comprehensive physical and mental health evaluation of geriatric patients.
Another recent study suggested that changes in the brain may play a role in chronic pain in older adults. Buckalew and colleagues8 compared MRI scans of geriatric patients with chronic low back pain with those of individuals without such pain. They found significant reductions in gray matter in the posterior parietal cortex in the older persons with low back pain. Although this research is preliminary, it does offer a suggestion about why pain may develop after traumatic injuries to the brain or as a result of changes in the brain from other diseases.
Patients with Parkinson disease, for example, commonly experience pain. Althouth it is often attributed as secondary to other signs of this disorder (eg, tremor and akinesia), it appears to be caused by underlying changes that result in these other problems.9
Even when pain is identified, physiological changes that are associated with aging and comorbid illnesses may restrict treatment options. For example, tricyclic antidepressants are among the most effective analgesics for a number of painful conditions—most notably, neuropathic pain—often experienced by geriatric patients. However, because of their potential to cause cardiac toxicity and adverse GI and CNS effects, they are generally contraindicated for elderly patients.10
The use of commonly employed analgesics can make geriatric patients more vulnerable to other health problems. Spector and colleagues11 found that anticonvulsants—another effective treatment for neuropathic pain—opioids, and antidepressants all increase the risk of fractures among nursing home residents.
All these factors make it extremely challenging to manage pain in geriatric patients. But we should not confuse challenging with impossible.